The present invention relates to a device for connecting bus bars having improved shape and characteristics.
More particularly, the connecting device according to the invention has a structure which allows to connect bus bars having any shape, be they variously shaped or flat, and with any connection configuration, being unique with respect to conventional devices owing to its extreme flexibility in use and to the simplicity of its production and assembly.
It is known that electric power distribution switchboards use, in order to distribute electric power to a plurality of electrical devices, such as for example circuit breakers, a system of mutually parallel metal bars which are arranged in an aligned or staggered configuration.
Each one of said bars is connected to a corresponding polarity of the electric power supply mains; the connection between the bus bars and the devices is provided by means of suitable conductors, such as for example laminae, which are shaped appropriately according to the type of device.
Inside the cabinets that accommodate the distribution switchboards, the configuration of the switchboards can be highly variable according to the different application requirements: thus, for example, the devices to which the bus bars are to be connected can vary in terms of type, shape and position; accordingly, the positions of the bars and the corresponding connection configurations to be provided are also extremely variable.
For example, two bars may be connected at right angles or in a T-shaped configuration or in other configurations, or a plurality of secondary bars may be connected along the entire extension of a same main bus bar which passes through one or more side-by-side cabinets.
In the current state of the art, these connections among bus bars are provided by virtue of connecting devices which have some drawbacks.
In particular, the main shortcoming of conventional connecting devices is their limited flexibility in use. If the mutual arrangement of the bus bars and their shape change, it is necessary to adopt differently shaped connecting devices, with consequent negative effects on production costs and on assembly difficulties.
An example in this regard is given by U.S. Pat. No. 5,364,203, which discloses a device for connecting two flat bus bars by means of an appropriately configured damper which is connected to the bars by means of bolts and nuts. Furthermore, the illustrated solution provides for bending the end portion of one of the two bars so as to surround laterally the other one and avoid any lateral shift thereof.
Although this solution is effective in the case of flat bars, it is entirely inapplicable to bars having different shapes and configurations; furthermore, the need to produce a hole in the bus bars and to bend them complicates production without significantly simplifying assembly in return. The fact should also be noted that when the bars to be connected conduct currents which have different amperages, the surface of contact between the connecting device and the bus bars must be sufficient to ensure correct and efficient conduction of the current between the bars. In the current state of the art, conventional devices are not suitable to universally connect the bus bars to each other, so that depending on the amperage levels involved it is necessary to adapt the dimensions of the devices to the specific practical application, entailing a consequent increase in production costs.
The aim of the present invention is to provide a device for connecting bus bars which is extremely flexible in use and allows, in particular, to connect bars having different shapes and with any mutual connecting arrangement.
Within the scope of this aim, an object of the present invention is to provide a device for connecting bus bars which is easy to manufacture and allows to significantly simplify the steps for connecting the bus bars inside electrical distribution switchboards.
Another object of the present invention is to provide a device for connecting bus bars which is capable of efficiently connecting bars that carry currents whose amperages are even considerably different from each other without having to modify the dimensions of said connecting device.
Another object of the present invention is to provide a device for connecting bus bars which is highly reliable, relatively easy to manufacture and at competitive costs.
This aim, these objects and others which will become apparent hereinafter are achieved by a device for connecting bus bars, characterized in that it comprises a body made of conducting material which has three elements which lie along three substantially mutually perpendicular planes, of which:
a first flat base element has a first outer side and a second outer side which are arranged in an L-shaped configuration with respect to each other, a third inner side and a fourth inner side being arranged in an L-shaped configuration with respect to each other and being substantially parallel to the corresponding outer sides;
a second flat element is arranged along said first outer side of the first element;
a third flat element is arranged along said second outer side or along said fourth inner side of the first element, the second flat element and the third flat element having such a length that their minimum relative distances allow the free passage of the bars, said first, second and third flat elements being further provided with a plurality of slots suitable to receive means for connection to the bars.
The connecting device according to the invention has the considerable advantage of allowing the connection of bus bars of any kind and shape, even flat ones; furthermore, the structure of the connecting device allows to connect the bus bars very simply and effectively, regardless of the bar connection configuration to be obtained and regardless of their arrangement inside the cabinets of the distribution switchboards.